The present invention relates to an illuminated buckle for a seat belt system and, in particular, to an illuminated buckle suitable for the seat belt system provided on the front seat of a vehicle.
Seat belt systems are provided on the seats of vehicles for restraining the occupants in case of collision and for protecting them against secondary impacts against internal parts of the vehicle. Such seat belts are usually placed over an occupant's body by inserting a tongue on the belt into a buckle. During nighttime or in other conditions of poor visibility, however, it is sometimes difficult for the occupant to locate the buckle in a non-illuminated vehicle.
To overcome this problem, it has been proposed in the prior art to provide an illuminating device on the buckle to illuminate parts of the buckle so that they are visible in darkness. For example, Japanese Provisional Utility Model Publication No. 54-76818 discloses an arrangement to illuminate the pushbutton of the buckle. Japanese Patent Publications No. 55-30366 and No. 55-30367 and Japanese Utility Model Publications No. 57-22803 or No. 63-42809 disclose an arrangement to illuminate the inlet edge of the buckle. Japanese Provisional Patent Publication No. 48-49126 discloses an arrangement to selectively illuminate both of the foregoing components. Japanese Provisional Utility Model Publication No. 61-36469 describes an arrangement to furnish an illuminating device within the ejector of the buckle.
In all of these conventional arrangements, however, the illuminating source, such as an electric bulb, LED, etc., is incorporated into the buckle. This results in problems of durability and maintenance inasmuch as trouble may occur due to overheating, wire disconnection, etc. It is particularly desirable to eliminate or minimize maintenance of the illumination components of the seat belt system, since such maintenance and the attendant risk of mistaken or negligent repair causes inconvenience and possible injury to the occupant in practice.